US 12,391,786 B2
Antioxidant for low-density polyurethane foam
Arvind Kumar, Bangalore North (IN); and Pranaya Man Singh Pradhan, Bangalore North (IN)
Assigned to SHELL USA, INC., Houston, TX (US)
Appl. No. 16/769,562
Filed by SHELL OIL COMPANY, Houston, TX (US)
PCT Filed Dec. 6, 2018, PCT No. PCT/EP2018/083777
§ 371(c)(1), (2) Date Jun. 3, 2020,
PCT Pub. No. WO2019/110726, PCT Pub. Date Jun. 13, 2019.
Claims priority of application No. 201741044114 (IN), filed on Dec. 8, 2017.
Prior Publication US 2020/0339727 A1, Oct. 29, 2020
Int. Cl. C08G 18/08 (2006.01); C08G 18/16 (2006.01); C08G 18/18 (2006.01); C08G 18/24 (2006.01); C08G 18/48 (2006.01); C08G 18/76 (2006.01); C08K 5/00 (2006.01); C08K 5/134 (2006.01); C08L 71/02 (2006.01); C08L 75/08 (2006.01)
CPC C08G 18/14 (2013.01) [C08G 18/4833 (2013.01); C08G 18/7621 (2013.01); C08K 5/005 (2013.01); C08K 5/1345 (2013.01); C08G 2110/0008 (2021.01); C08G 2110/005 (2021.01); C08G 2110/0083 (2021.01)] 12 Claims
 
1. A process for preparing a polyurethane foam comprising reacting a polyol component comprising a polyether polyol and a polyisocyanate in the presence of a blowing agent and one or more antioxidants, wherein:
the polyether polyol has (i) only propylene oxide moieties as alkylene oxide moieties or (ii) only propylene oxide moieties and ethylene oxide moieties as alkylene oxide moieties, the ethylene oxide moieties being present in an amount in the range of 1 to 25 wt. % based on the weight the polyether polyol;
the polyether polyol has a molecular weight in the range of 500 to 6000 Daltons;
the polyether polyol has a functionality of 2 to 5;
the polyether polyol has a primary hydroxyl content of from 1 to 50%;
the one or more antioxidants consist of one phenolic antioxidant or two or more phenolic antioxidants, wherein the one or two or more phenolic antioxidants contain no atoms other than carbon, hydrogen and oxygen, and the amount of the one or two or more phenolic antioxidants is of from 3,300 to 6,000 parts per million by weight (ppmw) based on the polyether polyol, and wherein only one or two or more phenolic antioxidants are used as the one or more antioxidants and substantially no non-phenolic antioxidant is present in the process;
the one phenolic antioxidant or at least one of the two or more phenolic antioxidants is a compound of the following Formula (II):

OG Complex Work Unit Chemistry
wherein
R1 is C4 alkyl,
n is 1,
X is —CH2CH2—C(═O)—O— where —CH2CH2 is bonded to the benzene ring and C(═O)—O— is bonded to R2, and
R2 is C16-C20 alkyl, or
the polyisocyanate is an aromatic polyisocyanate selected from toluene diisocyanate (TDI), polymeric TDI, xylylene diisocyanate, tetramethylxylylene diisocyanate, methylene diphenyl diisocyanate (MDI) or polymeric MDI or a modified product thereof;
the isocyanate index is from 110 to 150;
the blowing agent comprises water, and water is used in an amount of 4 to 8 parts per hundred parts by weight of the polyol component (pphp);
the maximum temperature during the preparation of the polyurethane foam is higher than 140° C. and not more than 190° C.; and
the density of the polyurethane foam is of from 6 to 20 kg/m3.